The emphasis of the University of Connecticut Health Center (UCHC) OAIC is musculoskeletal aging and its complications in older women. Intervention development studies (IDSs) to prevent or delay disability will be conducted, emphasizing bone health through prevention of osteoporosis and falls, coupled with aerobic and strength training. More broadly, the OAIC will create the infrastructure to support independence-promoting projects beyond musculo-skeletal aging by establishing Cores for Subject Recruitment and Retention (expert assistance in recruiting, scheduling, maintaining and retaining volunteers for OAIC and related projects; develop a registry of subjects for future studies) and for Outcomes Measurement (multidisciplinary measurement of physical performance, quality of life, bone biomarkers and cost-effectiveness) available not only to OAIC-funded projects, but also to relevant projects conducted by any UCHC research faculty. Epidemiology and Biostatistical Services will be provided for OAIC projects and activities by faculty and staff of the Epi/Biostat Core of UCHC's NIH-funded General Clinical Research Center (GCRC), supported in part by OAIC funds and in part by GCRC and UCHC contributions. Complementary IDSs will examine strategies to prevent bone loss and increase bone mass. IDS#1 will first determine the lowest dose of estrogen which will reduce bone turnover in older women; a second phase will determine if this estrogen regimen will not only reduce bone turnover, but also increase bone density and benefit other measures of health. Phase three will use molecular techniques on bone and marrow samples from a subset of study subjects to determine directly the influence of estrogen on an array of local factors known to modulate bone turnover. IDS#2 will study the effects of home exercise on bone density in older women already taking estrogen. Estrogen appears to function primarily as an anti-resorptive agent, thus preventing bone loss rather than increasing bone mass. For women on ERT who meet the new WHO criteria for low bone density, it is reasonable to consider exercise as adjunct therapy to reduce fracture risk. A major emphasis of IDS#2 is the development of a home-based exercise training program using low-cost equipment that leads to a high level of adherence and compliance. Together these investigations will address a central problem faced by older women (i.e., diminished mobility and functional status due to osteoporosis and the attendant risk of fracture). The UCHC OAIC will train and promote career development of new faculty committed to research in musculoskeletal aging and any other areas relevant to independence promotion and disability prevention for older adults by providing training, courses, mentoring and pilot project support. Finally, the OAIC will demonstrate benefits of the interventions and disseminate research findings to health professionals, to older adults and their families and to the public.